diff --git a/pretext/Control_Structures/conditionals.ptx b/pretext/Control_Structures/conditionals.ptx
index 12dffef..fecab26 100644
--- a/pretext/Control_Structures/conditionals.ptx
+++ b/pretext/Control_Structures/conditionals.ptx
@@ -1,8 +1,9 @@
-<?xml version='1.0' encoding='UTF-8'?>
 <section xml:id="control_-structures_conditionals">
         <title>Conditionals</title>
-        <p>Conditional statements in Python and C++ are very similar.</p>
-        <subsection xml:id="control_-structures_simple-if">
+        <introduction>
+<p>Conditional statements in Python and C++ are very similar.</p>
+        </introduction>
+<subsection xml:id="control_-structures_simple-if">
             <title>Simple if</title>
             <p>In Python, we write a simple if statement in the following way:</p>
             <pre>if condition:
diff --git a/pretext/Control_Structures/for_loop.ptx b/pretext/Control_Structures/for_loop.ptx
index 1c70c23..cd4cef7 100644
--- a/pretext/Control_Structures/for_loop.ptx
+++ b/pretext/Control_Structures/for_loop.ptx
@@ -1,7 +1,7 @@
-<?xml version='1.0' encoding='UTF-8'?>
 <section xml:id="control_-structures_for-loops">
         <title>For Loops</title>
-        <p>Even though the <c>while</c> type of construct is very useful in a wide variety of
+        <introduction>
+<p>Even though the <c>while</c> type of construct is very useful in a wide variety of
             situations, another iterative structure, the <c>for</c> <idx> <c> for </c> </idx> statement, can be
             used to iterate across a range of values easily.
             A <c>for</c> statement allows us to write a loop that is executed a specific number of times.</p>
@@ -41,7 +41,8 @@ using namespace std;
         <p>The code will use <c>cout</c> five times.  The value of the variable <c>i</c> will
             start at 0 and go through the full sequence of values 0,1,2,3,4.  This
             value is then squared and printed.</p>
-        <subsection xml:id="control_-structures_check-yourself">
+        </introduction>
+<subsection xml:id="control_-structures_check-yourself">
             <title>Check yourself</title>
             <pre>#include &lt;iostream&gt;
 using namespace std;